Surface treatment for a chair



FIG. 1 is a front view of the surface treatment for a chair.

FIG. 2 is a side view of the surface treatment for a chair of FIG. 1, the other side of the surface treatment for a chair being the mirror image of this view.

FIG. 3 is a top plan view of the surface treatment for a chair of FIG. 1.

The portions of the chair shown in broken lines have been shown for illustration purposes only and do not form part of the claimed design. 

The ornamental design for a surface treatment for a chair, as shown and described. 